Last night's Person of Interest, "Relevance," was quite simply superb. This show manages to do something that's practically impossible, which is somehow balance subtlety with hard-bitten action and broad humor. On the side of subtlety was a new wrinkle in the show's scifi subplot about the Machine's consciousness. On the action side, we met a kickass new character, and learned more about the shadowy intelligence organization that currently controls the Machine.

Written by Amanda Segel and show creator Jonathan Nolan, and directed by Nolan too, this was a pivotal episode, plus another piece of evidence that this show knows what it's doing. Its writers won't stop smashing down on the gas pedal until they burn through the finish line.

The show begins with its usual "You are being watched" opening, but then abruptly shifts to a Machine interface we haven't seen before. The red word "relevant" glows over top of a whirling montage of images, finally settling on a scene from a few years ago when a man named Aquino was shot while protesting that there must have been some mistake. This is our Machine, but a few clues immediately tip you off to the fact that we're seeing the intelligence agency's view. First, "relevant" crimes are highlighted, and we know that that's code for anything terrorist related. Remember, Reese and Finch only go after crimes the government deems "irrelevant." And! There is a quick view from a drone during this sequence. We've never seen drone surveillance footage before. I love a show that rewards close watching like this. Of course the government incorporates drone footage into its terrorism surveillance — but Reese and Finch don't get that view.

And finally, there are two individuals, Cole and Shaw, whose heads are surrounded by blue dotted boxes. (Reese and Finch are usually highlighted in yellow.) These are Finch and Reese's government counterparts and we're about to get to know them really well. Cole is the Finch of the operation, working behind the scenes with computers and surveillance equipment while Shaw holds the guns (and fights like a total badass). They're working for "Control," and their handler Wilson (playing a modern-day version of his weasely role on Boardwalk Empire) gives them numbers to track down from "Research." Right now, they're about to bust up a bunch of terrorist dirty bomb makers in Berlin.

There's poison gassing, punching, and shooting — then, Cole and Shaw hightail it back to New York to get details on their next number. But not all is well. Cole has been digging into that old case with Aquino that we saw highlighted in the Machine's memory banks in the episode opener, and he's started asking questions. It turns out Aquino wasn't getting money from Hezbollah — he was getting it from the US government. He's asked for an internal investigation. "Don't you ever wonder where research gets those numbers?" he asks Shaw. No, she says. Because they get those numbers "from a dark room where they hurt people badly." Still, Cole wants answers about Aquino.

And that's when things get pear-shaped. Shaw gets the latest number from Wilson, and she and Cole start shadowing a guy who has (like Aquino) suddenly gotten a bunch of money from a shady source. Meanwhile, we catch a glimpse of Reese shadowing Shaw. Looks like there are some overlapping numbers — or maybe the Machine just wants to introduce two of its favorite humans to each other. At any rate, the number mission turns out to be a trap. Cole is shot and killed and now Shaw — who is about as cool as you can get under pressure — is pissed. She wants revenge, and she wants to find out why Control set them up.

When Reese tries to come into the middle of the ambush to help her, she promptly shoots him multiple times. I love this character already. Then she escapes by pretending she wants to buy drugs from some guy on the street, then kidnaping him and forcing him to take her to his supplier. At the drug den, which is more like a nice apartment, she yanks a bullet out of her gut, passes out, but still manages to kill pretty much everybody in the place when threatened. Then she has a beer next to the dead bodies of some scummy drug dealers. This is a great scene of total badassery, where we learn that Shaw has an "Axis II personality disorder," which means she "doesn't really feel anything" when she kills people. Did I mention about loving this character? Shaw, be my Valentine.

Cut over to Special Counsel mystery guy, the intelligence honcho. He's the one who doesn't realize that his new secretary is evil hacker mastermind Root, who is trying to figure out where they keep the Machine so she can set it free. Special Counsel wants to know whether they can take down Shaw, and his adviser Hersch says pretty much no. She's so good that they won't find her unless she wants to be found.

Meanwhile, Root is listening to this whole conversation because she's bugged the shit out of SC's office. She figures out a way to horn in on the meeting that Shaw has set up with Veronica, who was going to help Cole do an internal investigation of the Aquino shooting (which — by the way, Shaw is the one who shot Aquino on orders from Control).

But all Root cares about is getting intel on the Machine. She wants to know who Cole's contact was in "Research." And this scene, where Root tries to torture the information out of Shaw, is pretty much priceless. Just watch it. OMFG. I love that Root and Shaw are pretty much flirting by the end, when Root is about to use the iron on Shaw's chest. Also love the bit about how stupid Shaw is for thinking that Research got their information from Guantanamo.

In the moments before this scene, however, Root spills some interesting information to Shaw. The group that SC runs (or kind of runs — he claims later he's not the real Control) is called Intelligence Support Activity, and Northern Lights is what this group calls the Machine. Apparently Aquino was killed because he built the special facility that houses the Machine for Intelligence Support Activity. So Root has been doing her homework — too bad she has to hightail it out of that seriously fucked up interrogation scene when more government guys arrive to kill Shaw.

But of course Shaw gets out of this bind too, until one of the agents stabs her with a poison needle. Luckily, Reese is there to pull it out and give us some "as you know Shaw" infodumpery about how you can counteract this poison and please remember this for later in the episode.

Reese brings Shaw to an abandoned building to meet Finch, who explains to Shaw that they "work for the same entity." Then he notes in characteristic Finch style, "The world looks like it did 10 years ago but . . . underneath an invisible struggle has begun." He tries to warn Shaw about how deep the rabbit hole goes and get her to at least team up with him and Finch. She refuses to take his phone number and says she doesn't need any help. She still has some revenge to do.

Then she stalks out of the building and calls up Wilson to tell him that she'll reveal everything about the Aquino case if he doesn't arrange a meeting between her and Control. And that's how she winds up chatting with SC about how Northern Lights is why "we haven't had another major attack" like 9/11. It's also when she reveals that she's still a loyal soldier — she's come to meet with him to give him the Aquino data and protect the intelligence community.

And then cue this fucking awesome scene. "A good soldier does both." Be still my heart. Great use of The Kills' song too. This leads to a quick montage where Hersch tries to poison Shaw on the street, Fusco and Carter pick her up and hand her over to Leon who is posing as an EMT. He delivers the aforementioned antidote to the poison and drops her off in a cemetery where she has another meeting with Reese and Finch.

This time, she takes Finch's phone number. (Here it is — you're welcome.) And his and Reese's phones, for good measure. (She knows about the force pair app.)

She's now on the same level with Finch and Reese. Finch explains, "Your employers wanted you dead and now you are." Shaw just gives him the Axis II personality stare and drives away in the ambulance.

Not likely. And that, people, is how you introduce a new character and show us a side to an ongoing character (the Machine) that we'd never seen before. Suddenly, we're having to grapple with the fact that the Machine is really two Machines, two entities — one that obeys the evil intelligence guys (who are also sometimes good guys like Shaw), and one that works with the good subversive guys (Finch and Reese). Is the Machine schizophrenic? Does it see any contradiction between its world of blue outlines and its world of yellow ones? What will happen when Root finally meets the Machine? Will she be able to exploit its split personality for her own nefarious ends?